Cost-effectiveness analysis of alternative water heater systems operating with unreliable water supplies

This paper reports on a cost-effectiveness analysis of four types of water heating systems operating in a situation where there is an unreliable water supply. These systems are electric water heating, a solar water heating system (SWHS) with electricity back-up, the SWHS with an LPG water heater, and an LPG water heater alone. It is found that in the conditions of North Cyprus, an SWHS with an LPG heater back-up is the most cost-effective, most convenient and most environmentally friendly system. The last two systems all have a cost per m 3 of hot water that is approximately 50% of the cost of heating water by electricity. This study finds that in situations where there is a winter or cloudy season, the choice of the source of energy for SWHS׳s back-up during this period is critical for its overall cost-effectiveness. When a pressurized supply of water is available, the cost of heating water is reduced by 20% for the SWHS with LPG back-up and for the heating of water by the LPG heater alone.